Linux命令PS

 

1. 列出所有的啟動並執行進程 (ps -ef, ps -aux)，在BSD機器上，需要使用ps -aux 
$ ps -ef
root     26551     5  0 Feb10 ?        00:03:41 [pdflush]
root     26570     5  0 Feb10 ?        00:00:20 [pdflush]
root     30344  3382  0 Feb21 ?        00:00:11 sshd: root@pts/14
root     30365 30344  0 Feb21 pts/14   00:00:02 -bash
root     30393  3382  0 Feb21 ?        00:00:10 sshd: root@pts/15

Where:
    -e to display all the processes.
    -f to display full format listing.

2. 基於使用者或啟動並執行程式來列出進程 (ps -u, ps -C)

-u選項用來顯示只屬於此user的進程。多個使用者時使用逗號隔開。
$ ps -f -u wwwrun,postfix
UID        PID  PPID  C STIME TTY          TIME CMD
postfix   7457  7435  0 Mar09 ?        00:00:00 qmgr -l -t fifo -u
wwwrun    7495  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun    7496  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun    7497  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun    7498  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun    7499  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   10078  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   10082  7491  0 Mar09 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
postfix  15677  7435  0 22:23 ?        00:00:00 pickup -l -t fifo -u

通常我們使用類似 “ps -aux | grep command”的命令來獲得運行命令的進程，但是ps自身提供了選項-C來完成類似的任務。下列的命令顯示所有進程中包含 tatad.pl的進程.
$ ps -f -C tatad.pl
UID        PID  PPID  C STIME TTY          TIME CMD
root      9576     1  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9577  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9579  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9580  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9581  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9582  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root     12133  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl

Note: We can create aliases for ps command to list processes based on commands, users or groups.

 

3. 根據進程id或pid來列出進程
Each process will be assigned with the unique Process ID (PID).
When you launch some application, it might fork number of processes and each sub process will have its own PID. So, each process will have its own process id and parent processid.
For all the processes that a process forks will have the same PPID (parent process identifier). The following method is used to get a list of processes with a particular PPID.

$ ps -f --ppid 9576
UID        PID  PPID  C STIME TTY          TIME CMD
root      9577  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9579  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9580  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9581  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root      9582  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl
root     12133  9576  0 Mar09 ?        00:00:00 /opt/tata/perl/bin/perl /opt/tata/bin/tatad.pl

The following example is to list the processes which has given PID.

$ ps -f  -p 25009,7258,2426
UID        PID  PPID  C STIME TTY          TIME CMD
root      2426     4  0 Mar09 ?        00:00:00 [reiserfs/0]
root      7258     1  0 Mar09 ?        00:00:00 /usr/sbin/nscd
postfix  25009  7435  0 00:02 ?        00:00:00 pickup -l -t fifo -u

4. 以樹形列出進程的關係(ps –forest) 與pstree命令類似
The example below display the process Id and commands in a hierarchy. –forest is an argument to ps command which displays ASCII art of process tree. From this tree, we can identify which is the parent process and the child processes it forked in a recursive manner.

$ ps -e -o pid,args --forest
  468  \_ sshd: root@pts/7
  514  |   \_ -bash
17484  \_ sshd: root@pts/11
17513  |   \_ -bash
24004  |       \_ vi ./790310__11117/journal
15513  \_ sshd: root@pts/1
15522  |   \_ -bash
 4280  \_ sshd: root@pts/5
 4302  |   \_ -bash

Note: You can also use tree and pstree command to displays process in a nice tree structure.

 

5. 顯示進程啟動並執行時間(ps -o pid,etime=)

If you want the get the elapsed time for the processes which are currently running ps command provides etime which provides the elapsed time since the process was started, in the form [[dd-]hh:]mm:ss.

The below command displays the elapsed time for the process IDs 1 (init) and process id 29675.

For example “10-22:13:29″ in the output represents the process init is running for 10days, 22hours,13 minutes and 29seconds. Since init process starts during the system startup, this time will be same as the output of the ‘uptime’ command.

# ps -p 1,29675 -o pid,etime=
  PID
    1 10-22:13:29
29675  1-02:58:46

 

 

參考：

http://www.thegeekstuff.com/2010/03/netstat-command-examples/http://www.thegeekstuff.com/2009/03/15-practical-linux-find-command-examples/http://www.thegeekstuff.com/2009/06/15-practical-unix-linux-find-command-examples-part-2/ http://www.thegeekstuff.com/2011/04/ps-command-examples/

 

完！